1. Field of the Invention
Exemplary embodiments of the disclosure relate to a display device and a contrast enhancement method thereof.
2. Discussion of the Related Art
Examples of a display device include a liquid crystal display (LCD), a field emission display (FED), a plasma display panel (PDP), and an organic light emitting diode (OLED) display. Most of them have been put to practical use in electric home appliances or personal digital appliances, etc. and have been marketed.
The image quality of the display device depends on contrast characteristic. U.S. Pat. No. 7,102,697 discloses an example of a method capable of improving the contrast characteristic. More specifically, U.S. Pat. No. 7,102,697 discloses a typical global contrast enhancement method. In U.S. Pat. No. 7,102,697, a luminance transfer curve is generated through a histogram analysis of a previous frame, and digital video data of a current frame is mapped to the luminance transfer curve, thereby performing a contrast enhancement of an image.
However, in U.S. Pat. No. 7,102,697, because the histogram analysis of the previous frame does not include detailed informations of the image, when a contrast ratio of the image uniformly increases, a detailed portion of the image is inevitably damaged. For example, when the contrast ratio of the image increases, a very dark portion in one frame becomes darker than an original image and a very bright portion in one frame becomes brighter than the original image. Therefore, the detailed portion of the image is inevitably damaged.